<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Update</title>
</head>
<body>
<h1>this is update page</h1>
<form action="/updateaction" method="post">
    username:{{ user[0] }} <input type="hidden" value="{{ user[0] }}" name="username"/>
    password:<input type="text" name="password">
    <input type="submit" value="update"/>

</form>
</body>
</html>